ANAT 1625 Thorax Notes (Updated Fall 10)

ANAT 1625 Thorax Notes (Updated Fall 10) - 1 Introduction...

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Introduction chapters ( COA ) Nervous system The nervous system enables the body to react to continuous changes in its internal and external environments It also controls and integrates the various activities of the body, such as circulation and respiration Structurally it is divided into 1. central nervous system ( CNS ) 2. peripheral nervous system ( PNS ) Functionally it is divided into 1. somatic nervous system ( SNS ) 2. autonomic nervous system ( ANS ) Nervous tissue consists of two main type of cells 1. neurons ( nerve cells ) 2. neuroglia ( glial cells ) that support the neurons Neuron is the structural and functional unit of the nervous system that is specialized for rapid communication It is composed of 1. cell body and processes 2. dendrites that carry impulses to the cell body 3. an axon that carries impulses away from the cell body Myelin is layer of lipid and protein substances from a myelin sheath around some axons greatly increasing the velocity of impulse conduction Synapses are points of contact between neurons where neurons communicate with each other The communication occurs by means of neurotransmitters , chemical agents released or secreted by one neuron, which may excite or inhibit another neuron, continuing or terminating the relay of impulses or the response to them Neuroglia are approximately five times as abundant as neurons, are nonneuronal, nonexcitable cells that form a major component of nervous tissue, supporting, insulating and nourishing the neurons In the CNS, neuroglia includes 1. oligodendrocytes 2. astrocytes 3. ependymal cells 4. microglia ( the smallest neuroglial cells ) In the PNS, neuroglia include 1. satellite cells around the neurons in the spinal ganglia ( dorsal root ganglia ) 1
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2. Schwann cells ( that form the myelin and neurolemmal sheaths around the peripheral nerve fibers Central nervous system Consists of the brain and spinal cord The principal roles of the CNS are 1. integrate and coordinate incoming and outgoing neural signals 2. carry out higher mental functions such as thinking and learning Nucleus is a collection of nerve cell bodies in the CNS Tract is a bundle of nerve fibers ( axons ) connecting the neighboring or distant nuclei of the CNS The brain and spinal cord consists of gray matter and white matter Gray matter is formed by the nerve cell bodies White matter is formed by the interconnecting fiber tract system In spinal cord cross section, the gray matter appears a H shaped area embedded in a matrix of white matter The supports of the H are the horns There are right and left dorsal ( posterior ) and ventral ( anterior ) horns Meninges are the three membranous layers and the cerebrospinal fluid surround and protect the CNS Piamater is a delicate, transparent covering, that intimately covers the brain and spinal cord The CSF is located between the piamater and the arachnoidmater Duramater is the thick and tough membrane external to the arachnoidmater, intimately related to the bone of the internal aspect of the neurocranium
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This note was uploaded on 11/22/2011 for the course ANAT 1625 taught by Professor Lescane during the Winter '11 term at Life Chiropractic College West.

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ANAT 1625 Thorax Notes (Updated Fall 10) - 1 Introduction...

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